He gave Mr. Sargsian until Wednesday to concede defeat. He promised another rally that day.

'Rampant violations'

Hovhannisyan supporters said they have hundreds of reports of illegal ballot stuffing or fraudulent ballot counting.

Sara Anjargolian, a lawyer at the rally, said she read reports of voting violations on Facebook pages of human rights groups, then went to Hovhannisyan’s headquarters to read reports coming in from voting stations.

“There were rampant violations - everything from ballot stuffing, and not one or two, but hundreds and hundreds and hundreds that were being stuffed for the sitting president,” she said. “And intimidation. Everything under the sun.”

But Eduard Sharmazanov, spokesman for Mr. Sargsian's ruling Republican Party, called the vote "the best in the history of independent Armenia."

Political analysts noted that last May, the Republican Party won 52 percent of seats in Armenia’s parliament. More recently, all pre-election polls indicated that voters heavily favored President Sargsian. After polls closed Monday night, a Gallup exit poll gave the president 58 percent of votes cast. On Tuesday morning, the Central Elections Commission gave him 58.64 percent.

Moscow approves

On Tuesday, the clearest election endorsement came from Armenia’s closest ally, Russia.

Sergei Lebedev, a former director of Russia’s Foreign Intelligence Service, headed a team of observers sent here from other former Soviet nations.

“Some minor irregularities that were spotted could not have affected the overall results of the presidential election,” Lebedev said. Armenia’s presidential election “fully meets generally recognized international norms and national electoral law,” he said.

Lebedev said violations were spotted but not enough to affect the overall results of the presidential election. He concluded that Armenia’s election fully meets generally recognized international law.

Russia maintains 5,000 troops in Armenia. On Tuesday, Russian President Vladimir Putin telephoned President Sargsian to congratulate him on his reelection.